摘要
目的探讨油酸诱导的急性肺损伤时肺泡液体的清除能力，以及肺泡Ⅱ型上皮细胞钠通道的变化。方法采用随机数字表法将44只雄性SD大鼠分为对照组和急性肺损伤组，每组22只大鼠。建立油酸肺损伤模型，急性分离肺泡Ⅱ型上皮细胞，透射电镜观察肺泡Ⅱ型上皮细胞的超微结构变化。每组均取8只大鼠进行逆转录（RT）-聚合酶链反应，检测肺泡Ⅱ型上皮细胞钠通道亚基mRNA的表达，7只大鼠用重力法测定血管外肺水含量，7只大鼠用于肺组织病理学检查。组问比较采用独立样本t检验和析因分析法，样本间两两比较采用q检验。结果急性肺损伤组大鼠肺损伤评分为（7．6±0．8）分，血管外肺水为（0．80±0．17）ml，均显著高于对照组[（1．1±0．2）分和（0．52±0．10）m1]，差异有统计学意义（t=-20．859，P〈0．01）电镜下肺泡Ⅱ型上皮细胞出现细胞变性、凋亡，板层小体排空等变化。RT-PCR显示肺泡Ⅱ型上皮细胞钠通道亚基表达以α-亚基为多，急性肺损伤组肺泡Ⅱ型上皮细胞钠通道α、β、γ亚基mRNA表达分别为（51±9）％、（13±7）％和（31±15）％，明显低于对照组[（82±7）％、（25±4）％和（40±17）％]，差异有统计学意义（t值为3．01—7．61，P〈0．05和P〈0．01）。结论急性肺损伤状态下，肺水的清除能力降低，肺泡Ⅱ型上皮细胞钠通道α、β和γ亚基表达均显著下降，钠通道转运功能受损。
Objective To determine the capability of alveolar fluid clearance and the changes of sodium channel in alveolar type Ⅱ cells （ AT Ⅱ ） in oleic acid-induced acute lung injury. Methods Forty four male Sprague-Dawley （SD） rats were randomized into a control group and an acute lung injury （ALI） group, with 22 rats in each group. The ALI model was established by oleic acid. The ATⅡ cells were acutely isolated and purified, and the AT Ⅱ cellular uhrastructure was observed by transmission electron microscope. In each group, the mRNA expression of 3 epithelial sodium channel （ENaC） subunits in acute isolated AT Ⅱ cells from 8 rats were detected by reverse transcription-polymerase chain reaction （ RT-PCR）, while the extravasular lung water （EVLW） content was quantified in 7 rats by gravimetric measurement, and the lung histopathological changes were studies in 7 rats. Results In the ALl group, Smith lung injury score （7.6 ±0. 8） and EVLW （0. 80 ±0. 17） ml were significantly higher than those in the control group [Smith score： （1.1±0.2）, t= -20.859, P〈0.01; EVLW： （0.52±0.10） ml, t= -3.851, P〈0.01]. The transmission electron microscopic observation showed that there were degeneration, apoptosis, and lamellar body vacuolar changes in the AT Ⅱ cells from the ALI rats. RT-PCR demonstrated that the α-subunit of the ENaC mRNA expression was the highest among the 3 subunits （ F = 4. 40, P = 0. 02）. In the ALI group, mRNA expressions of all the 3 ENaC subunits in acutely isolated AT Ⅱcells were decreased as compared to those in the control group [α-subunit ： （51 ± 9） % vs （ 82 ± 7 ） %, t = 7.61, P 〈 0. 01 ; β-subunit ： （ 13 ± 7）% vs （25±4）%, t=4.53, P 〈0. 01;γ-subunit： （31 ±15）% vs （40±17）%, t=3.01, P〈0.05; respectively]. Conclusions The capacity of alveolar fluid clearance was attenuated in oleic acid-induced acute lung injury. The ENaC subunit mRNA levels of AT Ⅱ cells were significantly decreased in ALl rats.
出处
《中华结核和呼吸杂志》
CAS
CSCD
北大核心
2009年第4期278-281,共4页
Chinese Journal of Tuberculosis and Respiratory Diseases
基金
基金项目：国家自然科学基金资助项目（30471720）
广东省医学科研基金资助项目（A2008404）
关键词
呼吸窘迫综合征
成人
肺泡
上皮钠通道
Respiratory distress syndrome, adult
Pulmonary alveoli
Epithelial sodiumchannel
